Although colonoscopy is not as painful as people thought in the past, active cooperation with the operating doctor during the process will be beneficial to reduce discomfort and shorten the operation time. Do not bring cell phones and other electronic devices into the operating room to avoid interference with the normal operation of the machine, and remove metal objects in contact with the body such as watches and glasses if you are ready to undergo colonoscopy. 2, after entering the operating room, the nurse sometimes injects Valium and atropine for the patient before starting to reduce the tension and discomfort brought about by colonoscopy. 3.Change the special pants (only the operating area near the anus is exposed) and position yourself according to the doctor’s requirements before the operation (usually in the left bent knee position). 4.During the operation, the doctor will slowly insert the lubricated colonoscope through the anus, during which you may feel bloated and have the urge to defecate due to the injection of gas into the intestinal cavity, and you may also feel pain due to the bending of the intestinal tube or adhesions. Do not waste your energy by shouting and prolong the consultation time by affecting the operation of the doctor. 5.Usually, the whole examination process will be completed in 20-30 minutes, and the treatment time will be extended accordingly depending on the degree of difficulty. 6, for patients with heart and lung diseases and other important organs, in the process of receiving colonoscopy also need to have heart and lung function monitoring. During the examination, if a lesion is found that cannot be diagnosed microscopically, the doctor will use biopsy forceps to remove a small amount of lesion tissue (this operation is called biopsy), put it in a specimen bottle with medicine and fix it and send it to the pathology department for further pathological histological diagnosis under the microscope. Since there is no nerve in the large intestine that can be pinpointed, the patient does not feel pain during the biopsy. Because the mucosa of the colon is constantly renewed like the skin, biopsy does not cause harm to the patient. However, sometimes bleeding may occur due to the rich vascularity of the lesion or because the patient is taking anticoagulant drugs, which is usually a small amount of bleeding that can be stopped by the colon itself.